Transporting device

ABSTRACT

The present disclosure relates to an apparatus and method for a load handling system such that direction change of a transporting device is more easily and quickly realised. A transporting device includes an omnidirectional driving unit, and is arranged to transport a container, the container being stored in a facility. The facility is arranged to store the container in a plurality of stacks, a plurality of pathways being arranged in cells so as to form a grid-like structure above the stacks, the transporting device being arranged to operate on the grid-like structure and to be driven in a first direction and/or second direction.

This application claims priority to U.S. patent application Ser. No.17/041,543 filed 25 Sep. 2020, which claims priority to InternationalApplication No. PCT/EP2019/057498 filed 26 Mar. 2019, which claimspriority from UK Patent Application No. 1804867.8 filed 27 Mar. 2018,the content of each prior application is hereby being incorporated byreference in its entirety.

TECHNICAL FIELD

The present invention relates generally to the field of transportingdevices. More specifically to a transporting device arranged to moveomnidirectionally.

BACKGROUND

Online retail businesses selling multiple product lines/batches/lots,such as online grocers and supermarkets, require systems that are ableto store tens or even hundreds of thousands of different product lines.The use of single-product stacks in such cases can be impractical, sincea very large floor area would be required to accommodate all of thestacks required. Furthermore, it can be desirable only to store smallquantities of some items, such as perishables or infrequently-orderedgoods, making single-product stacks an inefficient solution.

International patent application WO 98/049075A (Autostore), the contentsof which are incorporated herein by reference, describes a system inwhich multi-product stacks of containers are arranged within a framestructure.

PCT Publication No. WO2015/185628A (Ocado) describes a further knownstorage and fulfilment system in which stacks of bins or containers arearranged within a framework structure. The bins or containers areaccessed by load handling devices (also known as ‘transporting devices’)operative on tracks located on the top of the frame structure. The loadhandling devices lift bins or containers out from the stacks, multipleload handling devices co-operating to access bins or containers locatedin the lowest positions of the stack. A system of this type isillustrated schematically in FIGS. 1 to 4 of the accompanying drawings.

As shown in FIGS. 1 and 2 , stackable containers, known as bins 10, arestacked on top of one another to form stacks 12. The stacks 12 arearranged in a grid framework structure 14 in a warehousing ormanufacturing environment. FIG. 1 is a schematic perspective view of theframework structure 14, and FIG. 2 is a top-down view showing a stack 12of bins 10 arranged within the framework structure 14. Each bin 10typically holds a plurality of product items (not shown), and theproduct items within a bin 10 may be identical, or may be of differentproduct types depending on the application.

The framework structure 14 comprises a plurality of upright members 16that support horizontal members 18, 20. A first set of parallelhorizontal members 18 is arranged perpendicularly to a second set ofparallel horizontal members 20 to form a plurality of horizontal gridstructures supported by the upright members 16. The members 16, 18, 20are typically manufactured from metal. The bins 10 are stacked betweenthe members 16, 18, 20 of the framework structure 14, so that theframework structure 14 guards against horizontal movement of the stacks12 of bins 10, and guides vertical movement of the bins 10.

The top level of the frame structure 14 includes rails 22 arranged in agrid pattern across the top of the stacks 12. Referring additionally toFIGS. 3(a) and 4, the rails 22 support a plurality of robotic loadhandling devices 30. A first set 22 a of parallel rails 22 guidemovement of the load handling devices 30 in a first direction (X) acrossthe top of the frame structure 14, and a second set 22 b of parallelrails 22, arranged perpendicular to the first set 22 a, guide movementof the load handling devices 30 in a second direction (Y), perpendicularto the first direction. In this way, the rails 22 allow movement of theload handling devices 30 laterally in two dimensions in the horizontalX-Y plane, so that a load handling device 30 can be moved into positionabove any of the stacks 12.

One form of load handling device 30 is further described in Norwegianpatent number 317366, the contents of which are incorporated herein byreference. FIGS. 3(a) and 3(b) are schematic cross sectional views of aload handling device 30 depositing a bin 10, and FIG. 3(c) is aschematic front perspective view of a load handling device 30 lifting abin 10. However, there are other forms of load handling device that maybe used in combination with the system herein described. For example afurther form of robotic load handling device is described in PCT PatentPublication No. WO2015/019055, hereby incorporated by reference, (Ocado)where each robotic load handler only covers one grid space of the framework structure, thus allowing higher density of load handlers and thushigher throughput for a given sized system.

Each load handling device 30 comprises a vehicle 32 which is arranged totravel in the X and Y directions on the rails 22 of the frame structure14, above the stacks 12. A first set of wheels 34, consisting of a pairof wheels 34 on the front of the vehicle 32 and a pair of wheels 34 onthe back of the vehicle 32, is arranged to engage with two adjacentrails of the first set 22 a of rails 22. Similarly, a second set ofwheels 36, consisting of a pair of wheels 36 on each side of the vehicle32, is arranged to engage with two adjacent rails of the second set 22 bof rails 22. Each set of wheels 34, 36 can be lifted and lowered, sothat either the first set of wheels 34 or the second set of wheels 36 isengaged with the respective set of rails 22 a, 22 b at any one time.

When the first set of wheels 34 is engaged with the first set of rails22 a and the second set of wheels 36 is lifted clear from the rails 22,the wheels 34 can be driven, by way of a drive mechanism (not shown)housed in the vehicle 32, to move the load handling device 30 in the Xdirection. To move the load handling device 30 in the Y direction, thefirst set of wheels 34 is lifted clear of the rails 22, and the secondset of wheels 36 is lowered into engagement with the second set of rails22 a. The drive mechanism can then be used to drive the second set ofwheels 36 to achieve movement in the Y direction.

The load handling device 30 is equipped with a lifting device. Thelifting device 40 comprises a gripper plate 39 suspended from the bodyof the load handling device 32 by four cables 38. The cables 38 areconnected to a winding mechanism (not shown) housed within the vehicle32. The cables 38 can be spooled in or out from the load handling device32, so that the position of the gripper plate 39 with respect to thevehicle 32 can be adjusted in the Z direction.

The gripper plate 39 is adapted to engage with the top of a bin10/container. For example, the gripper plate 39 may include pins (notshown) that mate with corresponding holes (not shown) in the rim thatforms the top surface of the bin 10, and sliding clips (not shown) thatare engageable with the rim to grip the bin 10. The clips are driven toengage with the bin 10 by a suitable drive mechanism housed within thegripper plate 39, which is powered and controlled by signals carriedthrough the cables 38 themselves or through a separate control cable(not shown) or other communication mechanism.

To remove a bin 10 from the top of a stack 12, the load handling device30 is moved as necessary in the X and Y directions so that the gripperplate 39 is positioned above the stack 12. The gripper plate 39 is thenlowered vertically in the Z direction to engage with the bin 10 on thetop of the stack 12, as shown in FIG. 3(c). The gripper plate 39 gripsthe bin 10, and is then pulled upwards on the cables 38, with the bin 10attached. At the top of its vertical travel, the bin 10 is accommodatedwithin the vehicle body 32 and is held above the level of the rails 22.In this way, the load handling device 30 can be moved to a differentposition in the X-Y plane, carrying the bin 10 along with it, totransport the bin 10 to another location. The cables 38 are long enoughto allow the load handling device 30 to retrieve and place bins from anylevel of a stack 12, including the floor level. The weight of thevehicle 32 may be comprised in part of batteries that are used to powerthe drive mechanism for the wheels 34, 36.

As shown in FIG. 4 , a plurality of identical load handling devices 30are provided, so that each load handling device 30 can operatesimultaneously to increase the throughput of the system. The systemillustrated in FIG. 4 may include specific locations, known as ports, atwhich bins 10 can be transferred into or out of the system. Anadditional conveyor system (not shown) is associated with each port, sothat bins 10 transported to a port by a load handling device 30 can betransferred to another location by the conveyor system, for example to apicking station (not shown). Similarly, bins 10 can be moved by theconveyor system to a port from an external location, for example to abin-filling station (not shown), and transported to a stack 12 by theload handling devices 30 to replenish the stock in the system.

Each load handling device 30 can lift and move one bin 10 at a time. Ifit is necessary to retrieve a bin 10 (“target bin”) that is not locatedon the top of a stack 12, then the overlying bins 10 (“non-target bins”)must first be moved to allow access to the target bin 10. This isachieved in an operation referred to hereafter as “digging”.

Referring to FIG. 4 , during a digging operation, one of the loadhandling devices 30 sequentially lifts each non-target bin 10 a from thestack 12 containing the target bin 10 b and places it in a vacantposition within another stack 12. The target bin 10 b can then beaccessed by the load handling device 30 and moved to a port 24 forfurther transportation.

Each of the load handling devices 30 is under the control of a centralcomputer. Each individual bin 10 in the system is tracked, so that theappropriate bins 10 can be retrieved, transported and replaced asnecessary. For example, during a digging operation, the locations ofeach of the non-target bins 10 a is logged, so that the non-target bins10 a can be tracked.

The system described with reference to FIGS. 1 to 4 has many advantagesand is suitable for a wide range of storage and retrieval operations. Inparticular, it allows very dense storage of product, and it provides avery economical way of storing a huge range of different items in thebins 10, while allowing reasonably economical access to all of the bins10 when required for picking.

However, there are some drawbacks with such a system, which all resultfrom the above-described digging operation that must be performed when atarget bin 10 b is not at the top of a stack 12.

Moreover, a direction change of the transporting device is difficult toachieve. In particular, the above described system uses a complicatedand expensive direction change mechanism to raise and lower wheels ontwo faces of the transporting device such that only one set of wheels isin contact with the rails at a given moment to thereby permit atransporting device to move in orthogonal directions. These existingdirection change mechanisms slow down operation of the transportingdevice such that significant time is spent not moving laterally andinstead changing direction. Therefore a quicker and easier arrangementfor direction change is desirable.

SUMMARY

In view of the problems in known load handling systems, the presentinvention aims to provide an apparatus and method for such a loadhandling system such that direction change of the transporting device ismore easily, and more quickly, realised.

In general terms, the invention introduces an omnidirectional drivingunit which permits the transporting device to more easily move in morethan one direction.

According to the present invention there is provided a transportingdevice arranged to transport a container, the container being stored ina facility, the facility arranged to store the container in a pluralityof stacks, the facility comprising a plurality of pathways arranged incells so as to form a grid-like structure above the stacks, wherein thegrid-like structure extends in a first direction and in a seconddirection, the transporting device arranged to operate on the grid-likestructure. The transporting device comprises an omnidirectional drivingunit arranged to drive the transporting device in the first directionand/or the second direction.

The present invention also provides a storage system comprising a firstset of parallel rails or tracks extending in an X-direction, and asecond set of parallel rails or tracks extending in a Y-directiontransverse to the first set in a substantially horizontal plane to forma grid pattern comprising a plurality of grid spaces and a plurality ofstacks of containers located beneath the rails, and arranged such thateach stack is located within a footprint of a single grid space. Thestorage system further comprises at least one transporting device aspreviously described, the at least one transporting device beingarranged to move in the X and/or Y directions, above the stacks.

The present invention also provides a method of controlling atransporting device arranged to transport a container, the containerbeing stored in a facility, the facility arranged to store the containerin a plurality of stacks, the facility comprising a plurality ofpathways arranged in cells so as to form a grid-like structure above thestacks, wherein the grid-like structure extends in a first direction andin a second direction, the transporting device arranged to operate onthe grid-like structure. The method comprises driving,omnidirectionally, the transporting device in the first direction and/orthe second direction.

The present invention also provides a storage system comprising a firstset of parallel rails or tracks extending in an X-direction, and asecond set of parallel rails or tracks extending in a Y-directiontransverse to the first set in a substantially horizontal plane to forma grid pattern comprising a plurality of grid spaces, a plurality ofstacks of containers located beneath the rails, and arranged such thateach stack is located within a footprint of a single grid space, and atleast one transporting device, the at least one transporting devicebeing arranged to selectively move laterally in the X and Y directions,above the stacks on the rails. The at least one transporting devicecomprises a first set of wheels positioned on a first face of thetransporting device arranged to drive in the X-direction and a secondset of wheels positioned on a second face of the transporting devicearranged to drive in the Y-direction, the second face beingsubstantially perpendicular to the first face, the first set of parallelrails comprises a region in which, when the second set of wheels isdriven, the first set of wheels can move in the Y-direction, and thesecond set of parallel rails comprises a region in which, when the firstset of wheels is driven, the second set of wheels can move in theX-direction.

The present invention also provides method of controlling a storagesystem, the storage system comprising a first set of parallel rails ortracks extending in an X-direction, and a second set of parallel railsor tracks extending in a Y-direction transverse to the first set in asubstantially horizontal plane to form a grid pattern comprising aplurality of grid spaces, a plurality of stacks of containers locatedbeneath the rails, and arranged such that each stack is located within afootprint of a single grid space, and at least one transporting device.The at least one transporting device comprises a first set of wheelspositioned on a first face of the transporting device arranged to drivein the X-direction and a second set of wheels positioned on a secondface of the transporting device arranged to drive in the Y-direction,the second face being substantially perpendicular to the first face,wherein the first set of parallel rails comprises a region in which,when the second set of wheels is driven, the first set of wheels canmove in the Y-direction, and the second set of parallel rails comprisesa region in which, when the first set of wheels is driven, the secondset of wheels can move in the X-direction. The method comprisesselectively moving the transporting device laterally in the X and Ydirections.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described by way of exampleonly with reference to the accompanying drawings, in which likereference numbers designate the same or corresponding parts, and inwhich:

FIG. 1 is a schematic diagram of a framework structure according to aknown system.

FIG. 2 is a schematic diagram of a top-down view showing a stack of binsarranged within the framework structure of FIG. 1 .

FIGS. 3(a) and 3(b) are schematic perspective views of a load handlingdevice depositing a bin and FIG. 3(c) is a schematic front perspectiveview of a load handling device lifting a bin.

FIG. 4 is a schematic diagram of a system showing load handling devicesoperating on the framework structure.

FIG. 5 is a schematic diagram of a transporting device according to afirst embodiment of the present invention.

FIG. 6 is a schematic diagram of a side view of a transporting deviceaccording to a first embodiment of the present invention.

FIG. 7 shows a first example of the omnidirectional driving unitcomprising a ball.

FIGS. 8(a)-8(d)iii show examples of implementing the ball in thetransporting device.

FIGS. 9(a) and 9(b) show further examples of implementing the ball inthe transporting device.

FIGS. 10(a)-10(d) show yet further examples of implementing the ball inthe transporting device.

FIGS. 11(a)i-11(b)iv show yet further examples of implementing the ballin the transporting device.

FIGS. 12(a) and 12(b) shows a second example of the omnidirectionaldriving unit comprising an omniwheel.

FIGS. 13(a)-13(c) shows a third example of the omnidirectional drivingunit comprising a steerable wheel.

FIG. 14 shows a fourth example of the omnidirectional driving unitcomprising an air jet generator.

FIG. 15 shows a fifth example of the omnidirectional driving unitcomprising a linear motor.

FIG. 16 shows an example of a transporting device comprising anomnidirectional driving unit comprising at least one linear motor and asupporting unit comprising at least one ball.

FIG. 17 shows the fifth example of the omnidirectional driving unitcomprising at least one linear motor, where the at least one linearmotor is designed to operate on a flat rail.

FIG. 18 shows an example of a transporting device comprising anomnidirectional driving unit comprising linear motors and a supportingunit comprising balls designed to operate on a flat rail.

FIG. 19 shows a sixth example of the omnidirectional driving unitcomprising a magnetic flotation generator.

FIG. 20 shows a method according to the first embodiment.

FIG. 21 shows a first example of a transporting device according to thesecond embodiment of the present invention.

FIG. 22 shows a second example of a transporting device according to thesecond embodiment of the present invention.

FIG. 23 shows a method according to the second embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS First Embodiment

FIG. 5 shows a transporting device 100 according to a first embodimentof the present invention. The transporting device 100 is arranged tooperate on a grid 200. The grid 200 comprises a first set of parallelrails extending in a first direction (for example in an X-direction) anda second set of parallel rails extending in a second direction (forexample in a Y-direction). Where the first set and the second set ofrails meet forms an intersection. The transporting device 100 isarranged to move in the first direction and the second direction abovethe rails. Below the rails may be stacked containers forretrieval/deposition by the transporting device 100. The transportingdevice 100 achieves this by way of a receiving cavity (not shown) toreceive the container.

The grid 200 thereby forms a two-dimensional array of cells over whichthe transporting device 100 may move and stop to retrieve/deposit acontainer.

In this regard, the transporting device 100 of the first embodimentcomprises an omnidirectional driving unit 101 arranged to drive thetransporting device 100 in a first direction and/or a second direction.The omnidirectional driving unit 101 provides a number of advantagescompared to the existing solutions as described previously. Inparticular, the omnidirectional driving unit 101 permits thetransporting device 100 to change directions from the first direction tothe second direction or from the second direction to the first directionwithout the requirement to move wheels of the transporting device up ordown (i.e. in a third direction—for example a Z direction). As will bedescribed later, the present inventors have found that theomnidirectional driving unit 101 may be implemented in a number of ways,each with particular advantages.

The transporting device 100 may further comprise a supporting unit 102arranged to support the transporting device 100 above the grid 200. Thesupporting unit 102 may thereby be arranged to ensure that the body ofthe transporting device 100 (in other words, the features of thetransporting device 100 excluding the supporting unit 102) is placed atan appropriate distance from the grid 200 so that the transportingdevice 100 may conduct its operations of moving by way of theomnidirectional driving unit 101 and/or retrieving/depositing acontainer.

FIG. 6 shows a side view of the transporting device 100 shown in FIG. 5. As explained, the transporting device 100 is arranged to operate abovethe grid 200. Therefore, when moving across the grid 200 thetransporting device 100 may utilise the omnidirectional driving unit 101to move in at least one direction. The omnidirectional driving unit 101is arranged such that wheels need not be lifted up/dropped down onto therails so as to change direction. In this way, the speed of directionchange of the transporting device 100 may be increased. The transportingdevice 100 may further comprise a supporting unit 102 arranged tosupport the transporting device 100 at an operating distance from thegrid 200. In an example situation, the supporting unit 102 will bearranged to support the transporting device 100 against the force ofgravity which would otherwise pull the chassis/body of the transportingdevice 100 onto the grid and prevent the omnidirectional driving unit101 from moving the transporting device 100. However, in low/microgravity situations the supporting unit may instead be required to ensurethat the transporting device 100 remains in a relatively close proximityto the grid 200 and does not float free of an appropriate operatingdistance of the transporting device 100 from the grid 200. The presentinventors have considered a number of way of implementing the supportingunit 102, some of which contact the grid 200 and thereby support thetransporting device 100 against the force of gravity. In other example,they have utilised flotation techniques to counteract the force ofgravity using jets of air expelled from the bottom of the transportingdevice 100 and/or magnetic flotation techniques.

The present inventors also realised benefits when the omnidirectionaldriving unit 101 and supporting unit 102 are integrally formed. In thisway the omnidirectional driving unit 101 can be arranged to both providea driving force on the transporting device 100 and implement thesupporting unit 102 to keep the transporting device 100 at anappropriate operating distance from the grid 200. However, anomnidirectional driving unit 101 may be used in combination with adifferent supporting unit 102 to provide the best features of eachsolution, as will be described later.

In FIGS. 7 to 19 a number of examples of implementing theomnidirectional driving unit 101 and/or the supporting unit 102 will bedescribed.

FIG. 7 shows a transporting device 100 according to the first embodimentof the present invention. For clarity, the transporting device 100 isshown with a cavity 103 arranged to receive a bin/container from theplurality of stacks.

In this first example of the first embodiment, the omnidirectionaldriving unit 101 is provided by way of a substantially ball-shapedrolling means 700 arranged to roll in both a first direction and asecond direction. For example, a ball may be employed given itssubstantially spherical shape.

For ease of reference throughout the rest of the description asubstantially ball-shaped rolling means 700 will be referred to as “aball” although the skilled person will understand that a substantiallyball-shaped rolling means may not be limited to a ball. Optimally, theballs 700 are provided at each corner of the transporting device 100 soas to drive the transporting device 100 omnidirectionally across thegrid 200. As will be appreciated, the balls 700 may be placed in anylocation around the transporting device 100 that allows foromnidirectional movement. As shown in FIG. 7 , the balls 700 are shownplaced on the grid 200 by way of channels in the rails of the grid. Thisadvantageously permits the balls to more easily travel along the railswithout the necessity to steer the balls on the rails. The balls 700thereby provide a driving force to drive the transporting device 100 ina first direction or a second direction across the grid 200.

Optionally, the supporting unit 102 may be provided by way of the balls700 to keep the transporting device 100 at an operating distance fromthe grid. Therefore the balls 700 may be used to both support thetransporting device 100 at an operating distance from the grid and to bedriven to thereby move the transporting device 100 across the grid 200.

FIGS. 8(a) to 11(b)iv show examples of driving solutions and mountingsolutions for the balls 700 to the transporting device 100 which therebyprovide the necessary driving force and/or support force to move/supportthe transporting device 100.

FIG. 8(a) shows a first example of implementing a ball 700 as thesupporting unit 102. In FIG. 8(a) a ball 801 is formed of a materialsusceptible to being magnetised by a coil 802. In this way the ball 801forms an electromagnet. The ball operates on the surface 800 which, forexample, may be the surface of the rails of the grid 200. The ball 801magnetised by way of the coil 802 to repel a permanent magnet 803 tothereby create a frictionless bearing. The permanent magnet 803 may bemounted to the chassis/body of the transporting device 100. Thereby, therepulsive force effected on the permanent magnet 803 may be used as asupporting force for the transporting device 100 to ensure that thetransporting device 100 is maintained at an appropriate distance fromthe grid. To ensure the ball 801 remains appropriately positioned on thepermanent magnet 803, balancing electromagnets 804 are arranged aroundthe permanent magnet 803 and mounted to the chassis/body of thetransporting device 100. In this way the positioning of the ball 801 maybe maintained.

FIG. 8(b) shows a second example of implementing a ball 700 as theomnidirectional driving unit 101. FIG. 8(b) comprises a side view and aperspective view of the second example. In this example a ball 805 isarranged to operate on surface 800 such as the surface of the rails. Theball 805 may comprise a core formed of, for example, steel, and an outerregion of copper or aluminium. Optionally, to increase the lifetime ofthe ball 805 a hard wearing coating may be used around the copper oraluminium region. A two-dimensional linear motor 806 is provided todrive the ball in any/all of multiple directions to thereby provide anomnidirectional driving force.

FIG. 8(c) shows a third example of implementing a ball 700 as thesupporting unit 102. FIG. 8(c) comprises a side view and a perspectiveview of the third example. In this example a ball 807 is arranged tooperate on surface 800 such as the surface of the rails. The ball 807may be formed of a material such as aluminium or copper from which africtionless bearing may be formed. To increase the lifetime of the ball807 a hard wearing coating may be formed thereon. A spinning Halbacharray 808 mounted to the chassis/body of the transporting device 100 maybe used to induce a repulsive force in the ball 807 by way of the LenzEffect to thereby keep the spinning Halbach array 808 and the ballseparated to thereby provide the supporting unit 102. A dotted lineindicates the axis of polarisation of one of the permanent magnets inthe Halbach array. The nature of a Halbach array is that, in this case,alternate magnets may be polarised radially and tangentially to theball, FIG. 8(c) shows just the radial ones.

FIGS. 8(d)i-8(d)iii show a fourth example of implementing a ball 700 asthe omnidirectional driving unit 101 and/or the supporting unit 102.FIG. 8(d)i comprises a side view of the third example. FIG. 8(d)iicomprises a perspective view of a first variant of the fourth exampleand FIG. 8(d)iii comprises a perspective view of a second variant of thefourth example. In this example a ball 808 is arranged to operate onsurface 800 such as the surface of the rails. The ball 808 may be formedof a highly conductive material such as aluminium or copper from which africtionless bearing may be formed. To increase the lifetime of the ball807 a hard wearing coating may be formed thereon. Spinning Halbacharrays 809 may be formed around the ball 808 to induce a repulsive forcein the ball 808 by way of the Lenz Effect to thereby keep the spinningHalbach arrays 809 and the ball 808 separated to thereby provide thesupporting unit 102. In both variants, effective magnetic fields areradial to both the Halbach arrays 809 (formed as rings and/or wheels)and the ball 808. The Halbach arrays 809 work in pairs, each beingpaired with the Halbach array 809 opposite. In the variant of FIG.8(d)ii, the Halbach array 809 are arranged in a vertical plane as wheelswhich may be individually controlled. The wheels in one pair rotateabout their axes in the same direction as each other, in order togenerate both a lifting force and a turning force—thus generating drive.The other wheels may optionally be rotated about their axes in theopposite direction to each other in order to generate only lift.Alternatively, this second set of wheels may be rotated in the samedirection as each other to generate both a lifting force and a steeringforce. In the variant of FIG. 8(d)iii, the wheels in one pair rotate inthe opposite to each other as viewed from above (or in the samedirection if viewed along a line that passes through the centre of bothwheels) to generate both a lifting force and a turning force. The otherwheels may optionally be rotated about their axes in the same directionto each other (as viewed from above) in order to generate both a liftingforce and a steering force. Optionally, each spinning Halbach array 809may comprise at least one driving coil 810 (shown in FIG. 8(d)iii,however, may equally be applied to FIG. 8(d)ii) arranged to generate adrive force acting in a direction, which may be omnidirectional, tothereby move the transporting device 100.

FIG. 9(a) shows a fifth example of implementing a ball 700 as theomnidirectional driving unit 101 and/or the supporting unit 102. In thisexample a ball 901 is arranged to operate on surface 900 such as thesurface of the rails. The ball 901 is formed as a magnetic sphere, thesurface of which is formed from alternating magnetic poles. An array ofelectromagnets 902 are mounted to the chassis/body of the transportingdevice 100 and dynamically drive the transporting device 100 byenergising electromagnets 902 to thereby attract/repel the ball 901causing the transporting device 100 to move. Moreover, theelectromagnets 902 may be used to support the transporting device 100 ata predetermined distance from the rails of the grid 902 by energisingthe electromagnets 902 to levitate the transporting device 100 above theball 901 and above the rails of the grid 200. Alternatively, theelectromagnets 902 may be implemented as variable permanent magnets. Forexample, a cylindrical, yet hollow, permanent magnet may have a variablefield implemented by extending or retracting a soft iron core in intothe hollow centre of the magnet. At a distance from the variable magnetthe magnet polarity may thereby be caused to change. Similarly, a solidpermanent magnet may be held a variable distance from a soft iron coreto thereby decrease/increase the magnet field strength at a distancefrom the magnet. Alternatively, a cylindrical magnet, polarisedorthogonally to its axis, may be rotationally varied next to a soft ironcore comprising a convex end. In this way the magnetic field strength ata distance from the magnet may be varied. Alternatively, four permanentmagnets of alternating polarity may be arranged on a circular mountingnext to a cone shaped soft iron core such that as the mounting rotatesthe magnetic field strength at a distance varies.

FIG. 9(b) shows a sixth example of implementing a ball 700 as theomnidirectional driving unit 101 and/or the supporting unit 102. In thisexample a ball 903 is arranged to operate on surface 900 such as thesurface of the rails. The ball 903 may be rotationally supported by wayof ball bearings 905 against a mount 904 arranged to be mounted to thechassis/body of the transporting device 100. In this way, the ball 903,together with the ball bearings 905, may provide a supporting force totransporting device 100. Optionally, the ball bearings 905 may be madeof a magnetic material and the mount 904 may comprise a permanent magnetto hold the ball bearings in a location close to the mount 904 tothereby ensure easy rotation of the ball 903. Alternatively,frictionless bearings as described in previous examples may be usedinstead of ball bearings 905. To drive the ball 904 a drive wheel 906may be provided in contact with the ball 903. Moreover, a second drivewheel provided on an orthogonal axis of the ball 903 thereby provides anomnidirectional driving unit 101 which is arranged to move thetransporting device 100 in a direction.

FIG. 10(a) shows a seventh example of implementing a ball 700 as theomnidirectional driving unit 101. In this example a ball 1001 isarranged to operate on surface 1000 such as the surface of the rails. Inthis example the ball may be formed of steel whilst the rail 1000comprises at least one electromagnet 1002 arranged to attract the ball1001. In this way, the ball 1001 may be arranged to drive thetransporting device 100 by being attracted to the electromagnets 1002 sothat as the balls moves the transporting device 100 moves as well.Advantageously, this example does not require the powering of theomnidirectional driving unit 101 because the power requirements are onlypresent in the electromagnets 1002 present in the rail 1000.

FIG. 10(b) shows an eighth example of implementing a ball 700 as thesupporting unit 102. In this example a ball 1003 is arranged to operateon surface 1000 such as the surface of the rails. In this example theball 1003 may be formed of steel whilst a coil 1004 is mounted to thebody/chassis of the transporting device 100. Accordingly, energising thecoil 1004 causes an attractive force between the coil 1004 and the ball1003 thereby supporting the transporting device 100, shown as a payload1005.

FIGS. 10(c) and 10(d) show a ninth example of implementing a ball 700 asthe supporting unit 102. In this example a ball 1006 is arranged tooperate on surface 1000 such as the surface of the rails. FIG. 10(c)shows a side view of the apparatus and FIG. 10(d) shows a plan view. Inthis example the ball 1006 may be formed of steel whilst electromagnets1008 are mounted to the body/chassis of the transporting device 100,shown as a payload 1007. In this way, by energising the electromagnets1008 the transporting device 100 is supported at a predetermineddistance from the grid 200.

FIGS. 11(a)i and 11(a)iv show a tenth example of implementing a ball 700as the supporting unit 102. In this example a ball 1101 is arranged tooperate on surface 1100 such as the surface of the rails. FIGS. 11(a)iand 11(a)ii show a side view and a perspective view, respectively, of afirst variant of the tenth example. As shown in FIGS. 11(a)i and11(a)ii, a ball 1101 is provided comprising an outer ball and an innerball. The inner ball comprises electromagnets 1102 attached thereto.Between the outer ball and the inner ball is provided ball bearings. Inone example, the electromagnets 1102 are selectively energised to forman attraction to steel/ferritic elements 1103 positioned outside of theball 1101. The steel elements 1103 may be mounted to the transportingdevice 100, shown as a payload 1104. In this way, by energising theelectromagnets 1102 the transporting device 100 may be supported at apredetermined distance from the rail 1100. Therefore, this examplerelies on magnetic attraction to form a dynamic magnetic suspension.Alternatively, as shown in FIGS. 11(a)iii and 11(a)iv (which comprise aside view and a perspective view, respectively, of a second variant ofthe tenth example), the steel elements 1103 may be replaced withpermanent magnets 1105. In this way, magnetic repulsion may be used toform the dynamic magnetic levitation.

FIGS. 11(b)i-11(b)iv show an eleventh example of implementing a ball 700as the supporting unit 102. Similar to the tenth example a ball 1101 isarranged to operate on surface 1100 such as the surface of the rails.The ball 1101 is provided comprising an outer ball and an inner ball.However, different to the tenth example, the inner ball comprises atleast one permanent magnet 1107 fixed thereto. Between the outer balland the inner ball is provided ball bearings to allow the outer ball torotate around the inner ball. In one example, as shown in FIGS. 11(b)iand 11(b)ii a side view and a perspective view, respectively, of a firstvariant of the eleventh example is shown. As shown in FIGS. 11(b)i and11(b)ii, electromagnets 1108 are provided around the ball 1101. Byenergising the electromagnets 1108 the transporting device 100, which isshown as a payload 1104, may thereby be provided with a supporting forceto cause the transporting device 100 to be placed a predetermineddistance from the rail 1000. Alternatively, as shown in FIGS. 11(b)iiiand 11(b)iv (which comprise a side view and a perspective view,respectively, of a second variant of the eleventh example), theelectromagnets may be replaced by a permanent magnet 1109, which isenvisaged to be a ring magnet, and balancing coils 1110. The permanentmagnet 1109 and the balancing coils 1110 are envisaged to be fixed tothe chassis/body of the transporting device 100. In this way, asupporting force may be generated by a repulsive force between thepermanent magnets 1107 and 1109. Balance of the ball 1101 may beachieved by the balancing coils 1110. In this way, the transportingdevice 100 may be provided with a supporting force. Advantageously, inthis example power need not be provided to the inner ball.

FIGS. 12(a) and 12(b) show a transporting device 100 according to asecond example of the first embodiment of the present invention. In thissecond example of the first embodiment, the omnidirectional driving unit101 is provided by way of omniwheels 1200.

As shown in FIG. 12(a), an omniwheel 1200 comprises a wheel hub 1201which may be caused to rotate about an axis at the centre of the hub.Moreover, the omniwheel 1200 also comprises turning elements 1202 aroundthe circumference of the hub 1201 which are perpendicular to theturning/driving direction of the hub 1201. The effect is that the wheelcan be driven with full force, but will also slide laterally with greatease.

Optimally, the omniwheels 1200 are provided close to each corner of thetransporting device 100 so as to drive the transporting device 100omnidirectionally across the grid 200. As will be appreciated, theomniwheels 1200 may be placed in any location around the transportingdevice 100 that allows for omnidirectional movement. As shown in Figure,the omniwheels 1200 are shown placed on the grid 200 by way of channelsin the rails of the grid. This advantageously permits the omniwheels tomore easily travel along the rails without the necessity to steer theomniwheels on the rails. The omniwheels 1200 thereby provide a drivingforce to drive the transporting device 100 in a first direction or asecond direction across the grid 200. However, the omniwheels 1200 mustbe shaped to ride inside the channel of the grid 200 and, when movingaxially i.e. in a direction perpendicular to the direction of driving ofthe omniwheels 1200, so as not to interfere with any part of the rail.

Optionally, the supporting unit 102 may be provided by way of theomniwheels 1200 to keep the transporting device 100 at an operatingdistance from the grid. Therefore the omniwheels 1200 may be used toboth support the transporting device 100 at an operating distance fromthe grid and to be driven to thereby move the transporting device 100across the grid 200.

As shown in FIG. 12(b), to permit onmnidirectional movement, theomniwheels 1200 must be placed in a pattern on the transporting device100 to allow omnidirectional movement. The example shown in FIG. 12(b)shows the omniwheels 1200 placed in a diagonal pattern, with opposingcorners of transporting device 100 having the omniwheels 1200 aligned tobe driven in a first direction, in other words having their respectiveaxles aligned in a second direction. On the other hand, the omniwheelsof the remaining two corners of the transporting device 100 are alignedto be driven in a second direction, in other words having theirrespective axles aligned in a first direction. Other configurations arepossible. For example, each face of the transporting device 100 maycomprise two omniwheels 1200 aligned in the same direction (for example,as shown in FIG. 21 ). This permits driving of the omniwheels 1200 on afirst and second face of the transporting device 100 in a firstdirection whilst the omniwheels 1200 on a third and fourth faceslide/move laterally and vice-versa. Alternatively, four omniwheels 1200may be arranged on the transporting device 100 at each corner andangled, at, for example, 45 degrees to a face of the transporting device100. In this way, all four wheels of the transporting device 100 drivethe transporting device 100 causing movement by way of partial drivingand partial side-ways movements.

FIGS. 13(a) to 13(c) show a transporting device 100 according to a thirdexample of the first embodiment of the present invention. In this thirdexample of the first embodiment, the omnidirectional driving unit 101 isprovided by way of a steerable wheel 1300.

As shown in FIG. 13(a), a steerable wheel 1300 comprises a drivingsection 1301 and a steering section 1302. In this way, the wheel can besteered whilst being driven and may drive in any direction because anaxis of a drive shaft passes through the centre of each wheel. Thereby,the drive shaft is coaxial with the steering axis.

The large cog at the top of the steering section 1320 may turnindependently of the drive axle that passes through it (even though theyare coaxial), but is fixed to the support section 1302 below it: whenthe small cog turns, the large cog, together with the whole steeringsection 1302 turns together, and with them, the wheel and drivecomponents of the drive section 1301. Similarly, the wheel & cog at thebottom turn freely about the load-bearing axle that runs through them.

Optimally, steerable wheels 1300 are provided at each corner of thetransporting device 100 so as to drive the transporting device 100omnidirectionally across the grid 200, as shown in FIG. 13(b). As willbe appreciated, the steerable wheels 1300 may be placed in any locationaround the transporting device 100 that allows for omnidirectionalmovement. As shown in FIG. 13(b), the steerable wheels 1300 are shownplaced on the grid 200 by way of channels in the rails of the grid. Thisadvantageously permits steerable wheels 1300 to more easily travel alongthe rails. The steerable wheels 1300 thereby provide a driving force todrive the transporting device 100 in a first direction or a seconddirection across the grid 200. However, the steerable wheels 1300 mustbe shaped to ride inside the channel of the grid 200 and, when moving,steered so as not to move axially.

A single motor could be used to drive all of the steerable wheels 1300(with suitable drive shafts & gearing in between), and another motor,servo, linear motor or solenoid could be used to steer all 4 wheels, inunison, through 90 degrees. As described in the background section, atransporting device typically comprises 8 drive motors and 4 steeringmotors. Therefore the reduction to 1 of each motor suggests that drivefailure would be reduced to ⅙ its current rate. Moreover, fewer activecomponents makes the transporting device 100 lighter, cheaper, and moreefficient, and reduces the number of spares needed, maintenance effortand down time.

Such a transporting device 100 could be steered in any direction, butthe grid limits direction strictly to X & Y. However, in areas notconstrained to these directions, such as maintenance areas transportingdevice 100 need not be aligned to a grid. Thereby, maintenance areas maybe made easier to construct (i.e. simply a flat surface), manage, andless hazardous to work in (no holes in the floor/trip hazards).

Optionally, the supporting unit 102 may be provided by way of thesteerable wheel 1300 to keep the transporting device 100 at an operatingdistance from the grid. Therefore the steerable wheel 1300 may be usedto both support the transporting device 100 at an operating distancefrom the grid and to be driven to thereby move the transporting device100 across the grid 200.

FIG. 13(c) shows another implementation of the steerable wheel 1300. Inthis example, the driving section 1301 is provided by way of a motorbuilt into the hub of the wheel whereas the steering section 1302 isprovided similar to that shown in FIG. 13(a). Advantageously, thissimplifies the design and construction of the steerable wheel 1300.

With the steerable wheels shown in FIGS. 13(a) and 13(c) steering occursabout an axis that is orthogonal to the rail, intersecting the rail atthe intersection of the centre lines of the rails in a first directionand second direction. However, each wheel must not project into thespace above the adjacent rail, or it may interfere with the free travelof other transporting device 100 on that rail. This limits the wheeldiameter.

However, the present inventors have found that if the steering axis ofeach steerable wheel was away from the wheel, further in to thetransporting device 100, then the wheel could be located further back,and could travel in a small arc to steer allowing for a wider wheeldiameter without widening the rail.

FIG. 14 shows a transporting device 100 according to a fourth example ofthe first embodiment of the present invention. In this fourth example ofthe first embodiment, the omnidirectional driving unit 101 is providedby way of an air jet generator (not shown). The air jet generator may beincorporated into the body/chassis of the transporting device 100 and isarranged to generate jets of air which may selectively be expelled fromthe transporting device 100 by way of vents 1400 provided on orthogonalfaces of the transporting device 100. In this way, the jets may be usedto cause a force to act on the sides of the transporting device 100causing it to drive in a particular direction. As will be appreciated,with vents 1400 on the sides of the transporting device 100 then nosupporting force is being supplied to keep the transporting device 100at a predetermined distance from the grid. Accordingly, a supportingunit 102 as described previously, using, for example, balls, omniwheels,steerable wheels etc. may be used.

Alternatively, the present inventors have found that a vent 1400 may beprovided on the bottom of the transporting device 100 to provide aconstant air jet to thereby support the transporting device 100 againstthe force of gravity.

The air jet generator may be realised in a number of ways. For example,a propeller operating inside the transporting device 100 may be arrangedto cause the acceleration of air to be selectively vented from the vent1400. Alternatively, a tank of compressed air (or other gas) may be usedto vent the gas from the vents 1400 to thereby direct the transportingdevice 100.

FIG. 15 shows a transporting device 100 according to a fifth example ofthe first embodiment of the present invention. In this fifth example ofthe first embodiment, the omnidirectional driving unit 101 is providedby way of linear motors 1500 arranged on perpendicular faces. The linearmotors 1500 may be incorporated into the body/chassis of thetransporting device 100 and arranged to cause a force to act on thetransporting device 100 to thereby cause movement. To achieve this,rails with a high electrical conductivity, such as copper or aluminium,may be backed by steel, to complete the magnetic circuit. In this way,the linear motors 1500 in a first direction may cause movement in thatsame direction whilst linear motors 1500 in a second direction,perpendicular to the first direction may cause movement in the seconddirection. Although FIG. 15 shows linear motors on the sides of thetransporting device 100, it will be appreciated that linear motors mayinstead be mounted at the corners of the transporting device 100.Thereby, this example provides a linear induction motor, with linearmotors 1500 mounted within the transporting device 100 and a reactionplate (aluminium with a steel backing) mounted as rails.

As will be appreciated, the linear motors are unable to supply asupporting force to keep the transporting device 100 at a predetermineddistance from the grid. Accordingly, a supporting unit 102 as describedpreviously, using, for example, balls, omniwheels, steerable wheels etc.may be used.

Moreover, the rail shown in FIG. 15 includes a channel which is notnecessary for a transporting device 100 comprising linear motors.Therefore, the rail may instead be formed of a flat material containingaluminium or copper. This also permits the linear motors to be in closeproximity to the rails which maximises the driving force achieved by thelinear motors. Alternatively, the rail may be formed to provide areas(named ‘notched areas’) in which the linear motors can be moved withoutinterfering with the channel when moving against their direction ofdriving force.

However, when, for example, omniwheels are used as the supporting unit102 it may be advantageous to form the rails with a channel. However,this may result in the linear motors being spaced apart from the railwhich decreases the driving force of the linear motors. Accordingly, thepresent inventors have considered a lifting unit which may be employedto raise and lower the linear motors 1500 when moving in certaindirections. For example, for a transporting device 100 moving in a firstdirection, the linear motors are arranged to generate the force in thefirst direction may be lowered close to the rail whilst the linearmotors 1500 arranged to generate a force in the second direction may beraised to be clear of the channel. Similarly, when direction changeoccurs, the linear motors for the first direction may be raised whilstthe linear motors for the second direction may be lowered.Alternatively, the channel may comprise notches to allow the freemovement of the linear motors in close proximity to the rail.

FIG. 16 shows an example of the linear motors 1500 being used togetherwith balls 201. In this example, the omnidirectional driving unit 101comprises the linear motors 1500 whilst the supporting unit 102comprises the balls 201. As can be seen, the balls 201 run in thechannels of the rails, therefore it is advantageous to raise/lower thelinear motors 1500 where appropriate as previously described. The linearmotors 1500 are arranged to move the transporting device 100 in a firstdirection or a second direction and the balls 201 provide a supportingforce to keep the transporting device 100 an appropriate distance fromthe rails.

FIG. 17 shows an example where the linear motors 1700 have been extendedto the entire perimeter of the transporting device 100. When used inconjunction with the flat rail shown in FIG. 17 allows the transportingdevice 100 to move in a direction that is not purely a first directionor a second direction but a combination of the first and seconddirections. In other words, the transporting device 100 may be arrangedto move in a diagonal direction across the rails. Because the linearmotors 1700 extend the entire perimeter of the transporting device 100then there is no position on the rails from which the linear motor couldnot move the transporting device 100 because at least a part of thelinear motor is always in close proximity to a part of the rails.However, FIG. 17 does not show a supporting unit 102 arranged to providea supporting force on transporting device 100.

FIG. 18 shows an example similar to FIG. 17 , however, the supportingunit 102 is now provided by way of balls 201 around the perimeter of thetransporting device 100. In this way, the shown transporting device 100may operate on a flat rail because at least one ball 201 is in contactwith at least a part of a rail when the transporting device 100 ismoving diagonally such that the transporting device 100 is always beingprovided with an appropriate support force.

FIG. 19 shows a transporting device 100 according to a sixth example ofthe first embodiment of the present invention. In this sixth example ofthe first embodiment, the omnidirectional driving unit 101 is providedby way of at least one Lenz wheel 1901 arranged on, for example, acorner of the transporting device 100. The Lenz wheel 1901 may beincorporated into the body/chassis of the transporting device 100 and isarranged to cause a force to act on the transporting device 100 tothereby cause movement. The Lenz wheel may comprise a spinning Halbacharray which spins in a rail formed of copper half-pipe 1902 and whichcauses the spinning Halbach array to levitate and centre itself in thehalf-pipe. By tilting the Halbach array and/or reducing the speed ofsome Halbach arrays relative to other Halbach arrays then a differentialdriving force can be induced on the transporting device 100. In this waythe transporting device 100 may be moved by way of a driving forcegenerated by the Lenz wheel 1901.

Moreover, the supporting unit 102 may be formed by way of a spinningHalbach array in the copper half-pipe to thereby generate a supportingforce on the transporting device 100 to ensure the transporting device100 maintains an appropriate distance from the rail.

In this way, a magnetic levitation apparatus is used for theomnidirectional driving unit 101 and/or the supporting unit 102.

Similarly, the transporting device 100 may be provided withelectromagnets in the base thereof. When the electromagnets in the baseof the transporting device 100 are energised and used with a magneticrail then the transporting device 100 may levitate over the rail withamount of energisation in each coil being used to provide a supportingunit 102 to the transporting device 100 and ensure it maintains anappropriate distance from the rail. Similarly, by selectively energisingelectromagnets then a driving force may be caused to act on thetransporting device 100 so as to move the transporting device 100 in afirst and/or second direction based on the action of the electromagnetson the magnetic rail. Alternatively, the electromagnets may be placed inthe rail and the base of transporting device 100 made magnetic so thatcontrol of a supporting force and/or a driving force may be caused toact on the transporting device 100 by way of the electromagnets in therail. In this way, the power requirements of the transporting device 100may be reduced.

FIG. 20 shows a method S2000 according to the first embodiment of thepresent invention.

At step S2001 the method drives, omnidirectionally, a transportingdevice in a first direction and/or a second direction. In this way,movement across rails arranged in a grid can be easily achieved withoutthe necessity to move one set of wheels vertically which is slow therebyreducing transporting device 100 efficiency. As previously described, anumber of different means by which the transporting device 100 may bedriven have been described. In each case, the direction in which thetransporting device 100 may be moved may be easily achieved without a“direction change operation”.

At step S2002, optionally, a supporting force is provided to support thetransporting device above the grid. In this way, the distance betweenthe transporting device 100 and the grid can be optimally configured topermit both efficient movement of the transporting device 100 andoptimal retrieval/deposition of a container on the stacks of containers.

Second Embodiment

A second embodiment of the present invention is shown in FIGS. 21 and22. The second embodiment of the present invention is similar to thefirst embodiment except that modifications to the rail are made atselective points to permit the sliding of wheels mounted on the faces ofthe transporting device 100.

FIG. 21 shows a first example of the second embodiment of the presentinvention. In the first example, wheels 2101 similar to those used inexisting designs of the transporting device 100 may be used. Moreover,the rails are modified with a flat region 2102 at a slight differentlevel to the rest of the rail (for example, dropped by 1 mm compared tothe rest of the rail). Moreover the flat region 2102 of the rail doesnot feature the channel of the rest of the rail instead the railcomprises ‘notches’ in the side of the channel of the rail. Moreover,the flat region is positioned such that when the transporting device 100is located over a cell of the grid 200 to retrieve/deposit a containerthen the wheels 2101 and the flat region 2102 are coaxial, i.e. lined upwith one another. In this way, the wheels 2101 are able to slide/move ina direction of the axle across grid cells, which would otherwise beconstrained by the channel of the rails. In this regard, the directionof movement is perpendicular to the ‘normal’ movement direction of thewheels when driven, i.e. perpendicular to the direction of driving ofthe omniwheels 1200.

Therefore, when wheels 2102 to move the transporting device 100 in afirst direction are engaged, the wheels mounted to the transportingdevice 100 in the second direction are able to slide across the gridcell in the first direction and vice-versa.

Alternatively, the present inventors have found, advantageously, toprovide each wheel 2101 with a diameter adjusting unit. Therefore, therail with a lowered surface flat regions 2102 need not be provided lowerthan the surface of the rest of rail—the rail may be flat across itslength. In particular, because each wheel is typically the samediameter, then causing a wheel to slide/move axially causes wear on atyre of the wheel 2101, even with the lowered surface flat regions 2102.Therefore, the present inventors found that reducing the diameter of thewheels 2101 which are moving axially can reduce this wear because thetyre is then not in contact with the rail. For example, when the wheels2102 to move the transporting device 100 in a first direction areengaged, the wheels mounted to the transporting device 100 in the seconddirection are reduced in diameter and then able to slide across the gridcell in the first direction and vice-versa.

To achieve this the present inventors found that reducing the amount ofgas inflating the tyre of the wheel 2102 was an effective way to reducethe diameter of the wheel 2101. Moreover, the tyre may be inflated whenmovements in the complimentary direction is required. Alternatively, thepresent inventors have found that a magnetic means to contract the tyrewas also effective. To achieve this, the tyre is implanted with apermanent magnetic pole on an inner surface of the tyre and the hub ofthe wheel include the same pole next to an opposing magnetic pole whichis able to be rotated. Accordingly, when the tyre is to be contracted,the hub of the wheel is rotated to align opposing poles to thereby causethe tyre surface and the hub to be attracted thereby contracting thewheel diameter. Correspondingly, to expand the tyre, the hub is turnedagain so that alike magnetic poles are aligned to thereby repel the tyrefrom the hub resulting in an expansion of the tyre. Alternatively, thetyre surface may be mechanically manipulated by way of a spring, piston,electro-active material or the like to adjust the diameter of the wheel.

Alternatively, the wheels 2101 may be implemented as omniwheels, forexample as shown in FIG. 12(a) which allow movements in an axialdirection. In this regard, the ‘axial direction’ is the direction inwhich the axles of the omniwheels extend which is perpendicular to thedirection in which the omniwheel moves when driven. However, because theomniwheels are arranged to move axially (by way of turning elements)without the need for diameter adjustment then the flat regions 2102 neednot be provided lower than the surface of the rest of rail and nodiameter adjusting unit need be provided. In this sense, the rails areflat with a channel formed along a portion of the rail which means thatthe wheels 2102 need not be steered. As can be seen in FIG. 21 , atlocations where the wheels are to move axially the sides of the channelof the rail is removed/not installed to permit wheels 2101 which are tomove axially to do so. Therefore, when the transporting device 100 isaligned with a cell to deposit/retrieve a container then the sides ofthe channels at those locations is not installed. In this way, whenwheels are engaged to move in a first direction then the wheels onperpendicular sides can move in a second direction across the rails.

FIG. 22 shows a second example of the second embodiment of the presentinvention. In the second example, wheels 2201 similar to those used inexisting designs of the transporting device 100 may be used. Similar tothe first example of the second embodiment, the rails comprise ‘notches’to permit wheels not presently being driven to move perpendicular totheir driving direction i.e. in the direction in which their axlesextend. Moreover, the rails are modified to comprise a roller 2202. Theroller 2202 is arrange to rotate about an axle which is arranged in thedirection in which the rail extends. For example, if the rail extends ina first direction then the axis of rotation of the roller is alsoaligned with the first direction so that the roller rotates in a seconddirection. In this way, when the transporting device 100 is located in aposition to retrieve/deposit a container then the wheel may move in adirection perpendicular to its turning/driving direction to thereby movelaterally across the grid 200. The surface of the roller 2202 may bearranged to be parallel to a top surface of the grid 200 so thatmovement across the grid is not impeded by an uneven surface. Byutilising a roller 2202 the present invention have found that thesurface of a tyre of the wheel 2201 is not unnecessarily worn away by asliding motion required to move omnidirectionally. Instead, the rollers2202 permit an easier traversal of the grid for the wheels 2201 whenmoving in a direction perpendicular to their ‘usual motion’ i.e.perpendicular to a wheel's 2201 driving direction.

FIG. 23 shows a method S2300 according to the second embodiment of thepresent invention.

The method comprises a step S2301 which selectively moves,omnidirectionally, a transporting device in a first direction and asecond direction. In this way, movement across rails arranged in a gridcan be easily achieved without the necessity to move one set of wheelsvertically which is slow thereby reducing transporting device 100efficiency. As previously described, a number of different means bywhich the transporting device 100 may be driven have been described. Ineach case, the direction in which the transporting device 100 may bemoved may be easily achieved without a “direction change operation”.

Step S2302, optionally, may adjust the diameter of a first set of wheelsand/or a second set of wheels so that the wheel does not interfere withthe surface of the grid when the wheel is being moved axially/not beingdriven. In this way, excessive wear of the wheel can be avoided.

Modifications and Variations

Throughout the description a transporting device 100 has been shownoccupying a single space of the grid 200. However, a transporting device100 may be formed of any size so as to cover any integer number of cellsacross the grid. For example, a transporting device 100 may be formed tocover 2 cells in a first direction and 1 cell in a second direction.Alternatively, 2 cells in a first direction and 3 cells in a seconddirection. In this way, a transporting device 100 may be arranged toretrieve/deposit more than one container across the grid 200 at any onetime. Similarly, the transporting device 100 may be formed to containmore than one container in a third direction such as to store a stack ofcontainers within the body/chassis of the transporting device 100.

With regard to a transporting device 100 according to a fifth example,as shown in any of FIGS. 15 to 18 , further modifications to thisexample are envisaged. For example, the fifth example was previouslydescribed using linear induction motors, driving coils for which aremounted in the transporting device 100 with a corresponding reactionplate being formed in the rails (formed, for example, from aluminiumbacked by steel). However, it is envisaged that such an arranged may bereversed, with the reaction plate formed in the transporting device 100comprising steel to complete a magnetic circuit with a linear motor(comprising driving coils) formed in the rail. In this example, thelinear motors mounted in the rail are driven with appropriate currentsand voltages to induce an opposing voltage in the reaction plate in thetransporting device 100. Such induced currents and voltages may be usedto levitate the transporting device 100 and/or cause movement of thetransporting device 100 in a particular direction.

Alternatively, it is envisaged that linear synchronous motors may beused instead of linear induction motors shown in FIGS. 15 to 18 . Inthis modification, driving coils are mounted in a transporting device100 with corresponding permanent magnets mounted in the rail. In thisway, the combination of transporting device and rail is envisaged to bea linear synchronous motor. The driving coil in the transporting deviceis driven with appropriate voltages and currents to cause the setting upof a magnetic field which opposes the magnetic field of the permanentmagnets in the rail. Therefore, the transporting device 100 may belevitated and/or moved by selective application of voltages andcurrents.

Similarly, in this modification, the linear synchronous motor may beformed by mounting permanent magnets in the transporting device 100 withdriving coils mounted in the rail. In this way, levitation and/or motionof the transporting device 100 may be achieved by driving the coils withappropriate voltages and currents so cause the generation of a magneticfield around the rail which is repelled by the magnetic field of thepermanent magnets in the transporting device 100.

The foregoing description of embodiments of the invention has beenpresented for the purpose of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed. Modifications and variations can be made without departingfrom the spirit and scope of the present invention.

1. A transporting device configured to transport a container stored in afacility which has a plurality of stacks and a plurality of pathwaysarranged in cells so as to form a grid-like structure above the stacks,wherein the grid-like structure extends in a first direction and in asecond direction, the transporting device being configured to operate onthe grid-like structure, the transporting device comprising: a vehiclebody configured to accommodate one or more containers; anomnidirectional driving unit configured to drive the transporting devicein a first direction and in a second direction of a grid-like structure,the omnidirectional driving unit having plural driving components, eachof the plural driving components configured to apply a driving force tothe grid-like structure and move the transporting device in the firstdirection and the second direction; and a supporting unit arranged tosupport the transporting device at an operating distance from the grid,the supporting unit configured to apply a force to the transportingdevice that counteracts the force of gravity acting on the vehicle bodyof the transporting device.
 2. The transporting device according toclaim 1, wherein the plurality of driving components of theomnidirectional driving unit comprises at least one or more of: asubstantially ball-shaped rolling means; a wheel having turning elementsarranged perpendicular to a turning direction of the wheel; a steerablewheel; a gas jet generator; a linear motor; and a magnetic levitationgenerator.
 3. (canceled)
 4. The transporting device according to claim1, wherein the supporting unit comprises at least one or more of: asubstantially ball-shaped rolling means; a wheel having turning elementsarranged perpendicular to a turning direction of the wheel; a steerablewheel; a gas flotation generator; and a magnetic levitation generator.5. The transporting device according to claim 1, wherein theomnidirectional driving unit and the supporting unit are integrallyformed.
 6. The transporting device according to claim 4, comprising: thesubstantially ball-shaped rolling means, configured and arranged to movein a channel formed on the grid-like structure.
 7. The transportingdevice according to claim 6, wherein the substantially ball-shapedrolling means is arranged on a corner of the transporting device.
 8. Thetransporting device according to claim 4, wherein the steerable wheel ofthe omnidirectional driving unit is arranged on a corner of thetransporting device.
 9. The transporting device according to claim 2,comprising: the linear motor, the linear motor having a lifting unitconfigured and arranged to raise and lower the linear motor towards andaway from a grid-like structure.
 10. The transporting device accordingto claim 1, wherein the omnidirectional driving unit comprises: a linearmotor, and the supporting unit includes a substantially ball-shapedrolling means.
 11. The transporting device according to claim 1, whereinthe omnidirectional driving unit comprises: a linear motor arrangedaround a bottom face of the transporting device.
 12. The transportingdevice according to claim 1, wherein the omnidirectional driving unitcomprises: a linear motor arranged around a bottom face of thetransporting device, and the supporting unit includes a substantiallyball-shaped rolling means arranged around the bottom face of thetransporting device.
 13. A storage system comprising: a first set ofparallel rails or tracks extending in an X-direction, and a second setof parallel rails or tracks extending in a Y-direction transverse to thefirst set in a substantially horizontal plane to form a grid patternhaving a plurality of grid spaces; a plurality of stacks of containerslocated beneath the rails, and arranged such that each stack is locatedwithin a footprint of a single grid space; and at least one transportingdevice according to claim 1, the at least one transporting device beingconfigured and arranged to move in the X and Y directions, above thestacks.
 14. The storage system according to claim 13, wherein the atleast one transporting device has a footprint that occupies only asingle grid space in the storage system, such that a transporting deviceoccupying one grid space will not obstruct a transporting deviceoccupying or traversing adjacent grid spaces in the X and Y directions.15. A method of controlling a transporting device arranged to transporta container stored in a facility, the facility having a plurality ofstacks which can store the container, the facility including a pluralityof pathways arranged in cells so as to form a grid-like structure abovethe stacks, wherein the grid-like structure extends in a first directionand in a second direction, the transporting device being configured andarranged to operate on the grid-like structure, the method comprising:driving, omnidirectionally, the transporting device in the firstdirection and the second direction.
 16. (canceled)
 17. The storagesystem according to claim 13, wherein the at least one transportingdevice has a footprint that occupies only a single grid space in thestorage system, such that a transporting device occupying one grid spacewill not obstruct a transporting device occupying or traversing adjacentgrid spaces in the X and Y directions.
 18. (canceled)
 19. The storagesystem according to claim 18, wherein when the first set of wheels is tobe driven, the diameter adjusting unit is configured and arranged toreduce the diameter of the second set of wheels, and when the second setof wheels is to be driven, the diameter adjusting unit is configured andarranged to reduce the diameter of the first set of wheels.
 20. Thestorage system according to claim 19, wherein diameter adjusting unit isconfigured and arranged to adjust wheel diameter by at least one of:increasing/reducing an amount of a gas in the first set of wheels and/orthe second set of wheels; magnetically expanding/contracting a tiresurface of the first set of wheels and/or the second set of wheels;electro-mechanically adjusting a tire surface of the first set of wheelsand/or second set of wheels; and mechanical adjustment of a tire surfaceof the first set of wheels and/or the second set of wheels.
 21. Thestorage system according to claim 17, wherein the first set of wheelsand the second set of wheels comprise: a wheel having turning elementsarranged perpendicular to a turning direction of the wheel.
 22. Thestorage system according to claim 17, wherein a region of the first setof parallel rail comprises: a first roller arranged to rotate in theY-direction, and the second set of parallel rails includes a rollerarranged to rotate in the X-direction.
 23. (canceled)